lkml.org 
[lkml]   [2014]   [Feb]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v0 01/15] drivers: clk: st: Support for DIVMUX and PreDiv Clocks
Date
The patch supports the DIVMUX and PreDiv clocks used by ClockGenA(s)

DIVMUX clock : Divider-Multiplexer-Gate inside ClockGenA(s)
It includes support for each channel : 3-parent Multiplexer,
Divider for each Parent, Gate to switch OFF the output channel. The
clock is implemented using generic clocks implemented in the kernel
clk_divider and clk_mux.

PreDiv clock : Fixed Divider Clock used inside ClockGenA(s) to divide
the oscillator clock by factor-of-16. The clock is implemented using
generic clocks implemented in the kernel clk_divider.

Signed-off-by: Pankaj Dev <pankaj.dev@st.com>
Signed-off-by: Gabriel Fernandez <gabriel.fernandez@st.com>
---
drivers/clk/Makefile | 1 +
drivers/clk/st/Makefile | 1 +
drivers/clk/st/clkgen-mux.c | 529 ++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 531 insertions(+)
create mode 100644 drivers/clk/st/Makefile
create mode 100644 drivers/clk/st/clkgen-mux.c

diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index a367a98..7867c511 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -43,6 +43,7 @@ obj-$(CONFIG_ARCH_SHMOBILE_MULTI) += shmobile/
obj-$(CONFIG_ARCH_SIRF) += sirf/
obj-$(CONFIG_ARCH_SOCFPGA) += socfpga/
obj-$(CONFIG_PLAT_SPEAR) += spear/
+obj-$(CONFIG_ARCH_STI) += st/
obj-$(CONFIG_ARCH_SUNXI) += sunxi/
obj-$(CONFIG_ARCH_TEGRA) += tegra/
obj-$(CONFIG_ARCH_OMAP2PLUS) += ti/
diff --git a/drivers/clk/st/Makefile b/drivers/clk/st/Makefile
new file mode 100644
index 0000000..e42b370
--- /dev/null
+++ b/drivers/clk/st/Makefile
@@ -0,0 +1 @@
+obj-y += clkgen-mux.o
diff --git a/drivers/clk/st/clkgen-mux.c b/drivers/clk/st/clkgen-mux.c
new file mode 100644
index 0000000..65d702c
--- /dev/null
+++ b/drivers/clk/st/clkgen-mux.c
@@ -0,0 +1,529 @@
+/*
+ * clkgen-mux.c: ST GEN-MUX Clock driver
+ *
+ * Copyright (C) 2014 STMicroelectronics (R&D) Limited
+ *
+ * Authors: Stephen Gallimore <stephen.gallimore@st.com>
+ * Pankaj Dev <pankaj.dev@st.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+
+#include <linux/slab.h>
+#include <linux/of_address.h>
+#include <linux/clk-provider.h>
+
+static DEFINE_SPINLOCK(clkgena_divmux_lock);
+
+static const char ** __init clkgen_mux_get_parents(struct device_node *np,
+ int *num_parents)
+{
+ const char **parents;
+ int nparents, i;
+
+ nparents = of_count_phandle_with_args(np, "clocks", "#clock-cells");
+ if (WARN_ON(nparents <= 0))
+ return ERR_PTR(-EINVAL);
+
+ parents = kzalloc(nparents * sizeof(const char *), GFP_KERNEL);
+ if (!parents)
+ return ERR_PTR(-ENOMEM);
+
+ for (i = 0; i < nparents; i++)
+ parents[i] = of_clk_get_parent_name(np, i);
+
+ *num_parents = nparents;
+ return parents;
+}
+
+/**
+ * DOC: Clock mux with a programmable divider on each of its three inputs.
+ * The mux has an input setting which effectively gates its output.
+ *
+ * Traits of this clock:
+ * prepare - clk_(un)prepare only ensures parent is (un)prepared
+ * enable - clk_enable and clk_disable are functional & control gating
+ * rate - set rate is supported
+ * parent - set/get parent
+ */
+
+#define NUM_INPUTS 3
+
+struct clkgena_divmux {
+ struct clk_hw hw;
+ /* Subclassed mux and divider structures */
+ struct clk_mux mux;
+ struct clk_divider div[NUM_INPUTS];
+ /* Enable/running feedback register bits for each input */
+ void __iomem *feedback_reg[NUM_INPUTS];
+ int feedback_bit_idx;
+
+ u8 muxsel;
+};
+
+#define to_clkgena_divmux(_hw) container_of(_hw, struct clkgena_divmux, hw)
+
+struct clkgena_divmux_data {
+ int num_outputs;
+ int mux_offset;
+ int mux_offset2;
+ int mux_start_bit;
+ int div_offsets[NUM_INPUTS];
+ int fb_offsets[NUM_INPUTS];
+ int fb_start_bit_idx;
+};
+
+#define CKGAX_CLKOPSRC_SWITCH_OFF 0x3
+
+static int clkgena_divmux_is_running(struct clkgena_divmux *mux)
+{
+ u32 regval = readl(mux->feedback_reg[mux->muxsel]);
+ u32 running = regval & BIT(mux->feedback_bit_idx);
+ return !!running;
+}
+
+static int clkgena_divmux_enable(struct clk_hw *hw)
+{
+ struct clkgena_divmux *genamux = to_clkgena_divmux(hw);
+ struct clk_hw *mux_hw = &genamux->mux.hw;
+ unsigned long timeout;
+ int ret = 0;
+
+ mux_hw->clk = hw->clk;
+
+ ret = clk_mux_ops.set_parent(mux_hw, genamux->muxsel);
+ if (ret)
+ return ret;
+
+ timeout = jiffies + msecs_to_jiffies(10);
+
+ while (!clkgena_divmux_is_running(genamux)) {
+ if (time_after(jiffies, timeout))
+ return -ETIMEDOUT;
+ cpu_relax();
+ }
+
+ return 0;
+}
+
+static void clkgena_divmux_disable(struct clk_hw *hw)
+{
+ struct clkgena_divmux *genamux = to_clkgena_divmux(hw);
+ struct clk_hw *mux_hw = &genamux->mux.hw;
+
+ mux_hw->clk = hw->clk;
+
+ clk_mux_ops.set_parent(mux_hw, CKGAX_CLKOPSRC_SWITCH_OFF);
+}
+
+static int clkgena_divmux_is_enabled(struct clk_hw *hw)
+{
+ struct clkgena_divmux *genamux = to_clkgena_divmux(hw);
+ struct clk_hw *mux_hw = &genamux->mux.hw;
+
+ mux_hw->clk = hw->clk;
+
+ return (s8)clk_mux_ops.get_parent(mux_hw) > 0;
+}
+
+u8 clkgena_divmux_get_parent(struct clk_hw *hw)
+{
+ struct clkgena_divmux *genamux = to_clkgena_divmux(hw);
+ struct clk_hw *mux_hw = &genamux->mux.hw;
+
+ mux_hw->clk = hw->clk;
+
+ genamux->muxsel = clk_mux_ops.get_parent(mux_hw);
+ if ((s8)genamux->muxsel < 0) {
+ pr_debug("%s: %s: Invalid parent, setting to default.\n",
+ __func__, __clk_get_name(hw->clk));
+ genamux->muxsel = 0;
+ }
+
+ return genamux->muxsel;
+}
+
+static int clkgena_divmux_set_parent(struct clk_hw *hw, u8 index)
+{
+ struct clkgena_divmux *genamux = to_clkgena_divmux(hw);
+
+ if (index >= CKGAX_CLKOPSRC_SWITCH_OFF)
+ return -EINVAL;
+
+ genamux->muxsel = index;
+
+ /*
+ * If the mux is already enabled, call enable directly to set the
+ * new mux position and wait for it to start running again. Otherwise
+ * do nothing.
+ */
+ if (clkgena_divmux_is_enabled(hw))
+ clkgena_divmux_enable(hw);
+
+ return 0;
+}
+
+unsigned long clkgena_divmux_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clkgena_divmux *genamux = to_clkgena_divmux(hw);
+ struct clk_hw *div_hw = &genamux->div[genamux->muxsel].hw;
+
+ div_hw->clk = hw->clk;
+
+ return clk_divider_ops.recalc_rate(div_hw, parent_rate);
+}
+
+static int clkgena_divmux_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clkgena_divmux *genamux = to_clkgena_divmux(hw);
+ struct clk_hw *div_hw = &genamux->div[genamux->muxsel].hw;
+
+ div_hw->clk = hw->clk;
+
+ return clk_divider_ops.set_rate(div_hw, rate, parent_rate);
+}
+
+static long clkgena_divmux_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *prate)
+{
+ struct clkgena_divmux *genamux = to_clkgena_divmux(hw);
+ struct clk_hw *div_hw = &genamux->div[genamux->muxsel].hw;
+
+ div_hw->clk = hw->clk;
+
+ return clk_divider_ops.round_rate(div_hw, rate, prate);
+}
+
+static const struct clk_ops clkgena_divmux_ops = {
+ .enable = clkgena_divmux_enable,
+ .disable = clkgena_divmux_disable,
+ .is_enabled = clkgena_divmux_is_enabled,
+ .get_parent = clkgena_divmux_get_parent,
+ .set_parent = clkgena_divmux_set_parent,
+ .round_rate = clkgena_divmux_round_rate,
+ .recalc_rate = clkgena_divmux_recalc_rate,
+ .set_rate = clkgena_divmux_set_rate,
+};
+
+/**
+ * clk_register_genamux - register a genamux clock with the clock framework
+ */
+struct clk *clk_register_genamux(const char *name,
+ const char **parent_names, u8 num_parents,
+ void __iomem *reg,
+ const struct clkgena_divmux_data *muxdata,
+ u32 idx)
+{
+ /*
+ * Fixed constants across all ClockgenA variants
+ */
+ const int mux_width = 2;
+ const int divider_width = 5;
+ struct clkgena_divmux *genamux;
+ struct clk *clk;
+ struct clk_init_data init;
+ int i;
+
+ genamux = kzalloc(sizeof(*genamux), GFP_KERNEL);
+ if (!genamux)
+ return ERR_PTR(-ENOMEM);
+
+ init.name = name;
+ init.ops = &clkgena_divmux_ops;
+ init.flags = CLK_IS_BASIC;
+ init.parent_names = parent_names;
+ init.num_parents = num_parents;
+
+ genamux->mux.lock = &clkgena_divmux_lock;
+ genamux->mux.mask = BIT(mux_width) - 1;
+ genamux->mux.shift = muxdata->mux_start_bit + (idx * mux_width);
+ if (genamux->mux.shift > 31) {
+ /*
+ * We have spilled into the second mux register so
+ * adjust the register address and the bit shift accordingly
+ */
+ genamux->mux.reg = reg + muxdata->mux_offset2;
+ genamux->mux.shift -= 32;
+ } else {
+ genamux->mux.reg = reg + muxdata->mux_offset;
+ }
+
+ for (i = 0; i < NUM_INPUTS; i++) {
+ /*
+ * Divider config for each input
+ */
+ void __iomem *divbase = reg + muxdata->div_offsets[i];
+ genamux->div[i].width = divider_width;
+ genamux->div[i].reg = divbase + (idx * sizeof(u32));
+
+ /*
+ * Mux enabled/running feedback register for each input.
+ */
+ genamux->feedback_reg[i] = reg + muxdata->fb_offsets[i];
+ }
+
+ genamux->feedback_bit_idx = muxdata->fb_start_bit_idx + idx;
+ genamux->hw.init = &init;
+
+ clk = clk_register(NULL, &genamux->hw);
+ if (IS_ERR(clk)) {
+ kfree(genamux);
+ goto err;
+ }
+
+ pr_debug("%s: parent %s rate %lu\n",
+ __clk_get_name(clk),
+ __clk_get_name(clk_get_parent(clk)),
+ clk_get_rate(clk));
+err:
+ return clk;
+}
+
+static struct clkgena_divmux_data st_divmux_c65hs = {
+ .num_outputs = 4,
+ .mux_offset = 0x14,
+ .mux_start_bit = 0,
+ .div_offsets = { 0x800, 0x900, 0xb00 },
+ .fb_offsets = { 0x18, 0x1c, 0x20 },
+ .fb_start_bit_idx = 0,
+};
+
+static struct clkgena_divmux_data st_divmux_c65ls = {
+ .num_outputs = 14,
+ .mux_offset = 0x14,
+ .mux_offset2 = 0x24,
+ .mux_start_bit = 8,
+ .div_offsets = { 0x810, 0xa10, 0xb10 },
+ .fb_offsets = { 0x18, 0x1c, 0x20 },
+ .fb_start_bit_idx = 4,
+};
+
+static struct clkgena_divmux_data st_divmux_c32odf0 = {
+ .num_outputs = 8,
+ .mux_offset = 0x1c,
+ .mux_start_bit = 0,
+ .div_offsets = { 0x800, 0x900, 0xa60 },
+ .fb_offsets = { 0x2c, 0x24, 0x28 },
+ .fb_start_bit_idx = 0,
+};
+
+static struct clkgena_divmux_data st_divmux_c32odf1 = {
+ .num_outputs = 8,
+ .mux_offset = 0x1c,
+ .mux_start_bit = 16,
+ .div_offsets = { 0x820, 0x980, 0xa80 },
+ .fb_offsets = { 0x2c, 0x24, 0x28 },
+ .fb_start_bit_idx = 8,
+};
+
+static struct clkgena_divmux_data st_divmux_c32odf2 = {
+ .num_outputs = 8,
+ .mux_offset = 0x20,
+ .mux_start_bit = 0,
+ .div_offsets = { 0x840, 0xa20, 0xb10 },
+ .fb_offsets = { 0x2c, 0x24, 0x28 },
+ .fb_start_bit_idx = 16,
+};
+
+static struct clkgena_divmux_data st_divmux_c32odf3 = {
+ .num_outputs = 8,
+ .mux_offset = 0x20,
+ .mux_start_bit = 16,
+ .div_offsets = { 0x860, 0xa40, 0xb30 },
+ .fb_offsets = { 0x2c, 0x24, 0x28 },
+ .fb_start_bit_idx = 24,
+};
+
+static struct of_device_id clkgena_divmux_of_match[] = {
+ {
+ .compatible = "st,clkgena-divmux-c65-hs",
+ .data = &st_divmux_c65hs,
+ },
+ {
+ .compatible = "st,clkgena-divmux-c65-ls",
+ .data = &st_divmux_c65ls,
+ },
+ {
+ .compatible = "st,clkgena-divmux-c32-odf0",
+ .data = &st_divmux_c32odf0,
+ },
+ {
+ .compatible = "st,clkgena-divmux-c32-odf1",
+ .data = &st_divmux_c32odf1,
+ },
+ {
+ .compatible = "st,clkgena-divmux-c32-odf2",
+ .data = &st_divmux_c32odf2,
+ },
+ {
+ .compatible = "st,clkgena-divmux-c32-odf3",
+ .data = &st_divmux_c32odf3,
+ },
+ {}
+};
+
+static void __iomem * __init clkgen_get_register_base(
+ struct device_node *np)
+{
+ struct device_node *pnode;
+ void __iomem *reg = NULL;
+
+ pnode = of_get_parent(np);
+ if (!pnode)
+ return NULL;
+
+ reg = of_iomap(pnode, 0);
+
+ of_node_put(pnode);
+ return reg;
+}
+
+void __init st_of_clkgena_divmux_setup(struct device_node *np)
+{
+ const struct of_device_id *match;
+ const struct clkgena_divmux_data *data;
+ struct clk_onecell_data *clk_data;
+ void __iomem *reg;
+ const char **parents;
+ int num_parents = 0, i;
+
+ match = of_match_node(clkgena_divmux_of_match, np);
+ if (WARN_ON(!match))
+ return;
+
+ data = (struct clkgena_divmux_data *)match->data;
+
+ reg = clkgen_get_register_base(np);
+ if (!reg)
+ return;
+
+ parents = clkgen_mux_get_parents(np, &num_parents);
+ if (IS_ERR(parents))
+ return;
+
+ clk_data = kzalloc(sizeof(*clk_data), GFP_KERNEL);
+ if (!clk_data)
+ goto err;
+
+ clk_data->clk_num = data->num_outputs;
+ clk_data->clks = kzalloc(clk_data->clk_num * sizeof(struct clk *),
+ GFP_KERNEL);
+
+ if (!clk_data->clks)
+ goto err;
+
+ for (i = 0; i < clk_data->clk_num; i++) {
+ struct clk *clk;
+ const char *clk_name;
+
+ if (of_property_read_string_index(np, "clock-output-names",
+ i, &clk_name))
+ break;
+
+ /*
+ * If we read an empty clock name then the output is unused
+ */
+ if (*clk_name == '\0')
+ continue;
+
+ clk = clk_register_genamux(clk_name, parents, num_parents,
+ reg, data, i);
+
+ if (IS_ERR(clk))
+ goto err;
+
+ clk_data->clks[i] = clk;
+ }
+
+ kfree(parents);
+
+ of_clk_add_provider(np, of_clk_src_onecell_get, clk_data);
+ return;
+err:
+ if (clk_data)
+ kfree(clk_data->clks);
+
+ kfree(clk_data);
+ kfree(parents);
+}
+CLK_OF_DECLARE(clkgenadivmux, "st,clkgena-divmux", st_of_clkgena_divmux_setup);
+
+struct clkgena_prediv_data {
+ u32 offset;
+ u8 shift;
+ struct clk_div_table *table;
+};
+
+static struct clk_div_table prediv_table16[] = {
+ { .val = 0, .div = 1 },
+ { .val = 1, .div = 16 },
+ { .div = 0 },
+};
+
+static struct clkgena_prediv_data prediv_c65_data = {
+ .offset = 0x4c,
+ .shift = 31,
+ .table = prediv_table16,
+};
+
+static struct clkgena_prediv_data prediv_c32_data = {
+ .offset = 0x50,
+ .shift = 1,
+ .table = prediv_table16,
+};
+
+static struct of_device_id clkgena_prediv_of_match[] = {
+ { .compatible = "st,clkgena-prediv-c65", .data = &prediv_c65_data },
+ { .compatible = "st,clkgena-prediv-c32", .data = &prediv_c32_data },
+ {}
+};
+
+void __init st_of_clkgena_prediv_setup(struct device_node *np)
+{
+ const struct of_device_id *match;
+ void __iomem *reg;
+ const char *parent_name, *clk_name;
+ struct clk *clk;
+ struct clkgena_prediv_data *data;
+
+ match = of_match_node(clkgena_prediv_of_match, np);
+ if (!match) {
+ pr_err("%s: No matching data\n", __func__);
+ return;
+ }
+
+ data = (struct clkgena_prediv_data *)match->data;
+
+ reg = clkgen_get_register_base(np);
+ if (!reg)
+ return;
+
+ parent_name = of_clk_get_parent_name(np, 0);
+ if (!parent_name)
+ return;
+
+ if (of_property_read_string_index(np, "clock-output-names",
+ 0, &clk_name))
+ return;
+
+ clk = clk_register_divider_table(NULL, clk_name, parent_name, 0,
+ reg + data->offset, data->shift, 1,
+ 0, data->table, NULL);
+ if (IS_ERR(clk))
+ return;
+
+ of_clk_add_provider(np, of_clk_src_simple_get, clk);
+ pr_debug("%s: parent %s rate %u\n",
+ __clk_get_name(clk),
+ __clk_get_name(clk_get_parent(clk)),
+ (unsigned int)clk_get_rate(clk));
+
+ return;
+}
+CLK_OF_DECLARE(clkgenaprediv, "st,clkgena-prediv", st_of_clkgena_prediv_setup);
--
1.9.0


\
 
 \ /
  Last update: 2014-02-28 10:41    [W:0.106 / U:12.468 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site